No, if it's a FIDE and USCF rule and it can be implemented online, it can be implemented here. Should is a whole other issue that I'm sure takes more than just technical feasibility into account.
What do I do if someone repeatedly offers a draw when it is mate next move..??

Site owner's decision, Fezzik, and I'm not into telling Erik what to do on his website, he owns it, remember? you are here by your choice. choose to not participate in Erik's site? that is your choice. and it is (and should be) a free choice by each user... which site to attend and how much time to devote to it.
Regards,
site user.

Art. 9.1 b (1):
A player wishing to offer a draw shall do so after having made a move on the chessboard and before stopping his clock and starting the opponent’s clock. An offer at any other time during play is still valid but Article 12.6 must be considered.
If you want to make a draw offer, you should ("shall") do so at the end of your turn, but you can make the offer at any time and your opponent can accept it at any time. If you make the offer at any other point, you may suffer the consequences of 12.6, but that is only secondary and doesn't affect the validity of the offer. So no, chess.com handles this precisely like the FIDE rules would expect it to. Notably, FIDE rules don't know a three draw offers per move restriction, but presume the presence of an arbiter who would be capable of penalizing unsportsmanlike behaviour. Fezzik's proposal would this actually entail a departure from the FIDE rules, albeit backed by considerations of practicability within an online environment.
It's not easy to implement the FIDE (or, I would imagine, USCF) rules fully; many, many rules assume an OTB scenario. I assume that's why you won't find such an explicit inclusion on this site. But the spirit of the rules I would expect to stay alive. And that is: Players shouldn't act like rear ends in top hats, and if they do, you should be able to make them stop doing it.
(In this case, of course, simply ignoring the draw offer rather than explicitly declining it is the easiest way, and players should just do that instead of troubling the arbiters. I don't think Fezzik's recommendation is necessary with that in mind.)

Silfir, you are correct.
Obviously, if chess.com can not enforce 12.6., it could perhaps be better to implement the first sentence from the Article, play then draw.
When discussing the potential suggestions, one might think that a handy solution would be a "no draw" ,Sofia, flag. If you have it ticked, you would not see any draw offers, and the draw could only be claimed(3 move, 50 move, ...), not agreed.

Just ignore the offer and checkmate him. The game is over!
not possible.. on some other internet-chess sites you can only make draw offer during your opponents time. On this one you can make the offer whilst it is YOUR MOVE...so cannot simply checkmate have to go through this processs..

Art. 9.1 b (1):
A player wishing to offer a draw shall do so after having made a move on the chessboard and before stopping his clock and starting the opponent’s clock. An offer at any other time during play is still valid but Article 12.6 must be considered.
If you want to make a draw offer, you should ("shall") do so at the end of your turn, but you can make the offer at any time and your opponent can accept it at any time. If you make the offer at any other point, you may suffer the consequences of 12.6, but that is only secondary and doesn't affect the validity of the offer. So no, chess.com handles this precisely like the FIDE rules would expect it to. Notably, FIDE rules don't know a three draw offers per move restriction, but presume the presence of an arbiter who would be capable of penalizing unsportsmanlike behaviour. Fezzik's proposal would this actually entail a departure from the FIDE rules, albeit backed by considerations of practicability within an online environment.
It's not easy to implement the FIDE (or, I would imagine, USCF) rules fully; many, many rules assume an OTB scenario. I assume that's why you won't find such an explicit inclusion on this site. But the spirit of the rules I would expect to stay alive. And that is: Players shouldn't act like rear ends in top hats, and if they do, you should be able to make them stop doing it.
(In this case, of course, simply ignoring the draw offer rather than explicitly declining it is the easiest way, and players should just do that instead of troubling the arbiters. I don't think Fezzik's recommendation is necessary with that in mind.)
perhaps my point now becomes clear..
on this site you can make the draw offer without having made a move !
against the rules really..#

There's another difficulty to keep in mind: According to FIDE rules, you make your draw offer after making the move, but before hitting the clock. On chess.com, making the move "hits the clock" at the same time. Of course, simple enough: Just hit the draw offer button before you make the move, but the draw offer won't actually reach your opponent until the very second you have made your move and it's the opponent's turn. That would be a perfectly valid way to handle the issue.
@ netzach: Read more closely: Draw offers are valid at any time. You can make them at any time, you can just get in trouble if you distract your opponent that way. Chess.com adheres to FIDE rules in this matter, except that it's very hard to enforce 12.6 penalties for misconduct here since arbiters are (naturally) spread very thin.

I just noticed this, it appears that another rule is not followed here, so +1 to those who said chess.com has its own rules.
It's, move first, then offer a draw. The way OP described the situation, opponent was spamming draw offers but he did not move.
EXACTLY !.... that's why I became annoyed..

There's another difficulty to keep in mind: According to FIDE rules, you make your draw offer after making the move, but before hitting the clock. On chess.com, making the move "hits the clock" at the same time. Of course, simple enough: Just hit the draw offer button before you make the move, but the draw offer won't actually reach your opponent until the very second you have made your move and it's the opponent's turn. That would be a perfectly valid way to handle the issue.
A very good suggestion.

There's another difficulty to keep in mind: According to FIDE rules, you make your draw offer after making the move, but before hitting the clock. On chess.com, making the move "hits the clock" at the same time. Of course, simple enough: Just hit the draw offer button before you make the move, but the draw offer won't actually reach your opponent until the very second you have made your move and it's the opponent's turn. That would be a perfectly valid way to handle the issue.
A very good suggestion.
A very good suggestion.
provided you actually MAKE the move !!

But when he makes the draw offer during his move, his clock is still running down. If you just ignore the draw offer, he still has to move or lose on time. What is the big deal about "this process"?
In fact, the only way one can receive multiple draw offers on one move is by allowing oneself to get sucked in and continuing to decline them instead of just ignoring one. Instead of revisiting the game again and again while it is still your opponent's move and getting frustrated, why not just wait until you see it is your move?

There's another difficulty to keep in mind: According to FIDE rules, you make your draw offer after making the move, but before hitting the clock. On chess.com, making the move "hits the clock" at the same time. Of course, simple enough: Just hit the draw offer button before you make the move, but the draw offer won't actually reach your opponent until the very second you have made your move and it's the opponent's turn. That would be a perfectly valid way to handle the issue.
A very good suggestion.
A very good suggestion.
provided you actually MAKE the move !!
Well, the result is the same, minus the annoyance of the draw offers -- the injury may still be there, but at least the opportunity to add insult is not.

Do have to agree with Cystem_Phailure again (could be I already did, I write and write and forget what I wrote before): Simply ignoring the draw offer makes this a very minor inconvenience (of course, you can still offer one idiotic draw per move in the mating sequence). The debate on FIDE rules and their relation to chess.com rules that was spurred was quite interesting, however, so something good came out of this!

Players running out the clock is a seperate, much more infuriating issue. Sadly one that is also next to impossible to solve.
OTB, repeated draw offers wouldn't go unnoticed by kibitzers or other players present in the room (with the added benefit that the other players will be equally annoyed) and would lead to quick retribution by the arbiter. Players disappearing to run their clock out could also be pointed out. Possible technical solutions, however, are slight. Though I think there's already a two minute limit on disconnections before the game is abandoned and the win awarded to the remaining player.
There are reasons I only ever play blitz on here: Slow enough it's not quite as silly as bullet, fast enough I don't lose a lot of my time to rear ends in top hats.

chess.com should make the Draw Button to be available for clicking at most twice or thrice. If the player presses it the fourth time, then a message should appear saying "Loser! We're not even applying the Sofia Rules here."

Good idea, marvsC, and if you would volunteer to pay the programmer's time, maybe Erik would consider that idea.
until then, likely he has his programmers working on other priorities of greater interest to and for all users.
I was concentrated on spamming part, so I did not notice the "move then draw" part.